ar to Mr Hudson. This morning we were prepared at 9 at the Station
for some runs. Brunel and other people had arrived in the night. And
we have been to Darlington and back, with a large party in our
experimental train. George Arthur Biddell rode on the engine as
representing me. But the side wind was so dreadfully heavy that, as
regards the wants of the case, this day is quite thrown away. We have
since been to lunch with Vernon Harcourt (Mrs Harcourt not at home)
and then went with him to look at the Cathedral. The Chapter-house,
which was a little injured, has been pretty well restored: all other
things in good order. The Cathedral looks smaller and lower than
French cathedrals. Now that we have come in, the Lord Mayor of York
has just called to invite us to dinner to-morrow.--I propose to George
Arthur Biddell that he go to Newcastle this evening, in order to see
glass works and other things there to-morrow, and to return when he
can.

I think that I can persuade Barlow to stop to see the experiments out,
and if so I shall endeavour to return as soon as possible. The
earliest day would be the day after to-morrow.

* * * * *

The following extract is from a letter written to Mr Murray for
insertion in his Handbook of France, relating to the Breakwater at
Cherbourg, which Airy had visited during his journey in France in the
autumn of this year.

ROYAL OBSERVATORY, GREENWICH,
_1845, Oct. 8th_.

My opinion on the construction I need not say ought not to be quoted:
but you are quite welcome to found any general statement on it; or
perhaps it may guide you in further enquiries. To make it clear, I
must speak rather generally upon the subject. There are three ways in
which a breakwater may be constructed. 1. By building a strong wall
with perpendicular face from the bottom of the sea. 2. By making a
bank with nothing but slopes towards the sea. 3. By making a sloping
bank to a certain height and then building a perpendicular wall upon
it.--Now if the 1st of these constructions could be arranged, I have
no doubt that it would be the best of all, because a sea does not
_break_ against a perpendicular face, but recoils in an unbroken
swell, merely making a slow quiet push at the wall, and not making a
violent impact. But practically it is nearly impossible. The 2nd
construction makes the sea to bre